If it was a legit version, just do what they say to activate it. Call or activate over the internet. Or go to
http://www.microsoft.com and get their key changer and place their legit key and activation code in. If it is not a legit copy, I can't help you. I'm sorry, but I'm going to have to close this just because I can tell you right now it's going to go down the path of piracy, which we do not support.
PM me if it's a different story, and I will re-open it.